Q. Four lenses of focal length $+ 15\ cm,\ + 20\ cm, + 150\ cm$ and $+ 250\ cm$ are available for making an astronomical telescope. To produce the largest magnification, the focal length of the eye-piece should be
A) $+ 15\ cm$
B) $+ 20\ cm$
C) $+ 150\ cm$
D) $+ 250\ cm$
Explanation
(a) For largest magnification focal length of eye lens should be least
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.